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Sodium beacon wavefront sensing for the Euro50 telescope in the presence of perspective elongation

Beckers, Jacques M.; Owner-Petersen, Mette LU and Andersen, Torben LU (2004) Second Backaskog Workshop on Extremely Large Telescopes In Proceedings of the SPIE 5382. p.510-519
Abstract
To obtain full sky coverage, astronomical adaptive optics systemsrequire Na Sodium Beacons (SBs) (also referred to as Laser Guide Starsor LGSs) located at heights extending from 85 to 100 km. When viewed atthe edge of large telescopes these SBs appear elongated. For the Euro5050 meter aperture telecopes this elongation amounts to 6 to 9 arcsecondswhen the laser is launched from a point on the telescope axis. This issubstantially larger than the -0.6 arcsec FWHM SB when viewed near thetelescope center. This so-called "perspective elongation" substantiallydecreases the sensitivity of SB aided adaptive optics. We describe a wayof removing this elongation when using pulsed lasers. It uses rapid(microsecond) refocusing of the telescope with the... (More)
To obtain full sky coverage, astronomical adaptive optics systemsrequire Na Sodium Beacons (SBs) (also referred to as Laser Guide Starsor LGSs) located at heights extending from 85 to 100 km. When viewed atthe edge of large telescopes these SBs appear elongated. For the Euro5050 meter aperture telecopes this elongation amounts to 6 to 9 arcsecondswhen the laser is launched from a point on the telescope axis. This issubstantially larger than the -0.6 arcsec FWHM SB when viewed near thetelescope center. This so-called "perspective elongation" substantiallydecreases the sensitivity of SB aided adaptive optics. We describe a wayof removing this elongation when using pulsed lasers. It uses rapid(microsecond) refocusing of the telescope with the aid of birefringentlenses and polarization modulators. We present an outline of the SBwavefront sensor for the Euro50. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
in
Proceedings of the SPIE
editor
Ardeberg, Arne L.; Andersen, Torben; and
volume
5382
pages
510 - 519
publisher
SPIE
conference name
Second Backaskog Workshop on Extremely Large Telescopes
external identifiers
  • scopus:5444229878
ISBN
0-8194-5299-8
DOI
10.1117/12.566229
language
English
LU publication?
yes
id
bdd43380-5872-45d3-b19e-ef51a5178535 (old id 528501)
date added to LUP
2007-09-13 08:59:19
date last changed
2017-01-01 07:55:55
@inproceedings{bdd43380-5872-45d3-b19e-ef51a5178535,
  abstract     = {To obtain full sky coverage, astronomical adaptive optics systemsrequire Na Sodium Beacons (SBs) (also referred to as Laser Guide Starsor LGSs) located at heights extending from 85 to 100 km. When viewed atthe edge of large telescopes these SBs appear elongated. For the Euro5050 meter aperture telecopes this elongation amounts to 6 to 9 arcsecondswhen the laser is launched from a point on the telescope axis. This issubstantially larger than the -0.6 arcsec FWHM SB when viewed near thetelescope center. This so-called "perspective elongation" substantiallydecreases the sensitivity of SB aided adaptive optics. We describe a wayof removing this elongation when using pulsed lasers. It uses rapid(microsecond) refocusing of the telescope with the aid of birefringentlenses and polarization modulators. We present an outline of the SBwavefront sensor for the Euro50.},
  author       = {Beckers, Jacques M. and Owner-Petersen, Mette and Andersen, Torben},
  booktitle    = {Proceedings of the SPIE},
  editor       = {Ardeberg, Arne L. and Andersen, Torben},
  isbn         = {0-8194-5299-8},
  language     = {eng},
  pages        = {510--519},
  publisher    = {SPIE},
  title        = {Sodium beacon wavefront sensing for the Euro50 telescope in the presence of perspective elongation},
  url          = {http://dx.doi.org/10.1117/12.566229},
  volume       = {5382},
  year         = {2004},
}